This paper reports on a series of multi-agent-based simulation experiments. The purpose of these experiments is to investigate how factors like task-complexity, availability of skills and corporate policies determine the degree to which a firm may benefit from a specific, dedicated purchasing department. Particular attention is paid to the purchasing of non-product-related items and services. Among the factors investigated are: corporate purchasing policies, available information, capacity of organizational members and the nature of the various purchasing activities. Preliminary results suggest that most of these factors impact on the degree of involvement of a purchasing department as well as the quality of the purchasing activities carried out. The results show the limits of Purchasing's added value and the importance of organizational learning in that respect.